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(No Model.) 7 Q 'P. RICHARDS.

REVOLVING GOAL SCREEN. No. 361,185. Patented Apr. 12, 1887.

' WITNESSES 7 IJVVEJVTOR 7 .(U M. 11 N Jltto y proved revolving coal-screen.

UNITED STATES PATENT OFFICE.

PHILIP RICHARDS, OF PLYMOUTH, PENNSYLVANIA, ASSIGNOR OF THREE- FOURTHS TO JOHN H. RICHARDS, JOSEPH RODGER, AND JOHN ALFRED HAWK, ALL OF SAME PLACE.

REVOLVING COAL-SCREEN.

SPECIFICATION forming part of Letters Patent No. 361,185, dated April 12, 1887.

- Application filed September 10, 1886. Serial No. 213,225. (No model.)

To all whom it may concern.-

Be it known that I, PHILIP RICHARDS, of Plymouth, in the county of Luzerne and State of Pennsylvania, have invented certain new and useful Improvements in Revolving Coal- Screens; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, whioh form a part of this specification, and in which- Figure 1 is a perspective view of my im- Fig. 2 isalongitudinal vertical sectional view of the same, and Fig. 3 is a transverse sectional view.

Similar letters of reference indicate corresponding parts in all the figures.

My invention has relation to that class of revolving coal-screens in which the coalpasses through a revolving drum, dropping all the dirt through the apertures in the sides of the screen and emptying. the perfect coal at its end; and it consists in the improved construction of such a screen, in which the sides of the revolving drum are formed by flat twisted bars or slats having slightly-curved inner edges, between which the dirt may fall, and in which the coal may likewise have the slate screened out by having the bars placed at greater distances from each other, thus form ing a combined coal-screen and slate-separator, as hereinafter more fully described and claimed.

In the accompanying drawings, the letter A indicates an inclined floor having walls B,

' secured transversely upon it and. forming comwhich form the screening-surface of the cylinder, have their ends secured to these hoops.

The flat bars or slats are made of metal, and have their inner edges, L, curved slightly inward and overlapped by the outer edges of the adjoining slats, and the said bars are secured obliquely around the periphery of the drum, having each a spiral twist transverse to the axis of about one-fourth of the circumference of the drum.

A trough or chute, M, has its inclined innerend projecting into one end of the drum, and it will be seen that when coal is filled into the drum through this chute and the former is revolved the curved edges of the bars will catch the dirt, which will fall out between the slats, while the coal will pass out of the rear end of the drum, being too large to pass through the spaces of the screen, and the said curved edges will cause the coal to slide along them on account of their twist and will catch the dirt and shake the coal during the revolution of the drum, cleaning the coal more effectually than a screen having the common perforated sides.

By securing the bars or slats with larger spaces between them the slate may be picked or screened from the coal, the inwardlycurved edges of the slats or bars engaging the flat edges of the slate and allowing it to drop out through the spaces, while the rounder sides of the lumps of coal will roll over the edges and pass down through the cylinder or drum.

This screen may likewise be used for separating coal into different sizes by having the bars arranged with differentsized spaces between them, the smaller coal dropping out though the smaller spaces and the larger coal passing along to the rear end of the screen,

the inwardly-curved edges of the slats and their twist serving to more thoroughly screen the coal than screens having simple perforations.

The bins or compartments into which the coal and dirt fall are preferably provided with slidesN at their lower-ends, allowing the contents to be removed from them in the desired quantities.

Having thus described myinvention, Ielaini In testimony that I claim the foregoing as r 5 and desire to secure by Letters Patent of the my own I have hereunto affixed my signature United Statesin presence of two witnesses.

A drum-shaped rotary eoalsoreen compris- 5 ing hoops or rings forming its heads or ends, PHILIP RICHARDS.

and a series of spirallyset bars forming its perimeter or screening-surface, said bars be- Witnesses: ing arranged to partially overlap one another I). \V. EVANS, and having their overlapped edges slightly J. A. OPP.

ro curved inward, substantially as described. 1 

